Note that this plugin controls some options and setting the option in the config file will have no
effect. These include specifying source to be measured (source option) and all data file handling
(data_file and parallel options).

Limitations

For subprocess measurement environment variables must make it from the main process to the
subprocess. The python used by the subprocess must have nose2-cov installed. The subprocess must
do normal site initialisation so that the environment variables can be detected and coverage
started.

Acknowledgements

Whilst this plugin has been built fresh from the ground up it has been influenced by the work done
on pytest-coverage (Ross Lawley, James Mills, Holger Krekel) and nose-cover (Jason Pellerin) which are
other coverage plugins.

Ned Batchelder for coverage and its ability to combine the coverage results of parallel runs.